The present invention relates to the field of photography and, more specifically, to film processing apparatus for applying a low viscosity processing liquid to an outer surface of an exposed sheet-like photosensitive film unit to initiate processing thereof.
It is recognized that substantial cost reductions may be realized in self-developing or self-processing film systems if the film unit can be treated with a low viscosity (having a consistency similar to water) processing liquid rather than the jelly-like higher viscosity liquid employed in most commercially available systems. This is because higher viscosity liquids require the use of mechanically complex and relatively expensive spread control structures in the film unit, cassette and camera (e.g. precision rollers) to achieve uniform fluid distribution over a given surface of the exposed film unit. On the other hand, low viscosity liquids tend to be more self-spreading and uniform distribution may be readily achieved without having to resort to elaborate and costly spread control systems.
Representative examples of self-developing film systems wherein the outer surface of an exposed photosensitive sheet is wetted with a low viscosity liquid to initiate processing may be found in U.S. Pat. No. 3,179,517 and commonly assigned U.S. Pat. Nos. 3,314,792; 3,345,165 and 3,907,563 wherein a processing web roll that is pre-soaked with a low viscosity liquid, or is wetted just prior to processing, is brought into face-to-face contact with an exposed photosensitive sheet to wet its outer surface and initiate the development process. Also, see commonly assigned U.S. Pat. Nos. 3,069,266 and 3,498,203 for examples of structures wherein a low viscosity processing liquid is delivered to the exposed film surface by means of various capillary action applicators.
One problem with these systems is that if the entire web is not used within a very short time after its container is opened, it is very difficult to protect the unused portion of the web from being contacted by the atmosphere which will cause the liquid to evaporate or combine with atmospheric oxygen and carbon dioxide which tends to diminish the chemical effectiveness of the processing liquid. Also, residual liquid on the capillary action applicators tends to dry out and crust over thereby blocking liquid transport passageways therein.
U.S. Pat. No. 4,310,620 discloses a low viscosity processing liquid applicator in the form of an absorbent spreading sheet or pad that is soaked with a low viscosity processing liquid and is laminated on both sides with a foil which is impervious to water. The foil sheets form an enclosure to protect the wet pad against evaporation and contamination. Just before use, one of the foil sheets is stripped off to expose the impregnated spreading sheet which is then brought into contact with the film unit surface. However, there is no teaching or even suggestion of an apparatus that is configured to easily manipulate such applicators and conveniently store the surplus material after use for disposal.
Commonly assigned and co-pending applications, U.S. Ser. Nos. 436,189 and 436,078 (now U.S. Pat. No. 4,401,381) filed on Oct. 22, 1982, and U.S. Ser. Nos. 445,416 and 445,417, filed on Nov. 30, 1982, are directed to individual selfprocessing film units, each having a low viscosity liquid applicator attached to one end thereof and to processing apparatus for manipulating such applicators.
For some commercial and industrial applications it may be more convenient and economical to provide the applicators separate from the film units. For example, the applicators could be provided on a separate multi-container liquid applicator packaging web comprising an elongated carrier sheet, a plurality of processing liquid soaked pads attached to one side of the carrier sheet in spaced apart relation along its length, and an elongated flexible cover sheet overlying the carrier sheet in covering relation to the applicator pads. The carrier and cover sheets may be releasably sealed together in facing areas thereof surrounding each of the applicator pads to form a plurality of serially connected pouch-like containers on the web, each enclosing a corresponding one of the applicator pads therein.
What is needed is a processing apparatus for manipulating such an applicator packaging web so as to sequentially uncover the wet applicator pads as needed by stripping away the cover sheet therefrom, presenting an uncovered applicator pad at a processing position, and storing surplus material, including the expended applicator pads, for subsequent disposal.
Commonly assigned U.S. Pat. No. 2,558,857 discloses a photographic developer element comprising a water and vapor impervious sheet that is coated with a very high viscosity processing liquid layer. When rolled into a coil, the impervious sheet protects the next length of liquid coating. However, there is no cover sheet per se that has to be removed to provide access to the processing liquid layer.
Therefore, it is an object of the present invention to provide a film processing apparatus that is configured for use with such a multi-container liquid applicator packaging web employing releasably sealed carrier and cover sheets.
It is another object to provide such a film processing apparatus that is capable of advancing the web in such a manner so as to strip the cover sheet from the carrier sheet to provide successive access to applicator pads thereon.
Yet another object is to provide such a film processing apparatus that stores the expended web components for subsequent disposal.
Another object is to provide such a film processing apparatus that is easy to use.
Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.